Plaque chemistry and caries incidence will be determined in 12-16 month old monkeys maintained on a cariogenic diet, with and without supplements of potential anti-cariogenic substances: pyridoxine and sodium inositol phosphate. Plaque samples obtained before and during the feeding experiments will be examined for numbers of microorganisms producing extracellular and intracellular polysaccharides, and also for the quantities of calcium phosphorus, magnesium, carbohydrate, and protein. The identity of the acids produced in situ by plaque from sugars in the different diets will be determined.